Render a Wicket page to a string for HTML email

protected String renderPage(Class<? extends Page> pageClass, PageParameters pageParameters) {

		//get the servlet context
		WebApplication application = (WebApplication) WebApplication.get();

		ServletContext context = application.getServletContext();

		//fake a request/response cycle
		MockHttpSession servletSession = new MockHttpSession(context);
		servletSession.setTemporary(true);

		MockHttpServletRequest servletRequest = new MockHttpServletRequest(
				application, servletSession, context);
		MockHttpServletResponse servletResponse = new MockHttpServletResponse(
				servletRequest);

		//initialize request and response
		servletRequest.initialize();
		servletResponse.initialize();

		WebRequest webRequest = new WebRequest(servletRequest);

		BufferedWebResponse webResponse = new BufferedWebResponse(servletResponse);
		webResponse.setAjax(true);

		WebRequestCycle requestCycle = new WebRequestCycle(
				application, webRequest, webResponse);

		requestCycle.setRequestTarget(new BookmarkablePageRequestTarget(pageClass, pageParameters));

		try {
			requestCycle.request();

			log.warn("Response after request: "+webResponse.toString());

			if (requestCycle.wasHandled() == false) {
				requestCycle.setRequestTarget(new WebErrorCodeResponseTarget(
						HttpServletResponse.SC_NOT_FOUND));
			}
			requestCycle.detach();

		} finally {
			requestCycle.getResponse().close();
		}

		return webResponse.toString();
	}

12 thoughts on “Render a Wicket page to a string for HTML email”

1. Hi Dan,

   thanks for the post, that seems to be exactly what I’m looking for.

   Copying the code into my app, I got a compiler error on the line where the WebRequest is created. Using the constructor to ServletWebRequest helped.

   Nonetheless, I get only an empty string back, no clue whats going wrong.

   I’m using Wicket 1.3.5.

2. We are also using Wicket in combination with Spring. Wouldn’t it be easier to use Spring + Velocity to generate HTML Emails?

   http://www.theserverside.com/tt/blogs/showblog.tss?id=SpringVelocityEmail

   Although I would prefer a solution that is more tied to Wicket, the Spring solution seems to be easier to grab and thus more maintainable IMHO.

   I never tried it any of the above, but will have to in the next couple of months.

3. Got it working by replacing requestCycle.request() with requestCycle.getProcessor().respond(requestCycle);

   Thanks for sharing!

4. and by changing
   new WebRequest(servletRequest);
   to
   new ServletWebRequest(servletRequest);

5. I have a similar problem – something that should be easy to do, and may already be available from the API (I am still usin 1.3.5).

   How can one duplicate rendered strings? In other words, I am trying to render once but copy a number of times for better performance – e.g., putting a page navigator both at the top and bottom of the list (the bottom is simply a label generated from copying the rendered top one). I tried using onRendered to copy getResponse.toString() for later reuse, but renderComponent() throws IllegalStateException: page not found – even though I am adding the component to a panel as instructed by Component.renderComponent() – any ideas? Thx

6. Hey guys – use wicket-test this is the framework for testing but can render panels or entire pages to a string. It does use a fake web application so you might need to hack some things if you require funky web application setups

7. I have some BookmarkablePageLink in the page I want to render. They are rendering just a part of the url, for instance

   http://www.miapp.com/asd/asd/asd

   it renders only

   /asd/asd/asd

   which its wrong because users read it in their email program. How can I instruct BookmarkablePageLink to render the whole url?

   thanks in advance

8. Dan,
   I have to send emails from another servlet. In this case, I need a mock application to get it working. I try to build my own without success. Dummy Application says it has not attached a ServletContext. I got it from WicketTester. Any idea how to build mails from a servlet that is not a WicketFilter or wicket servlet?

9. Hi,
   is there a possibility to use this code snippet for components (i.e. MarkupContainer) instead of bookmarkable pages? I didn’t find a way to change this. Maybe someone can help me?

10. Thanks Andrew Williams for mentioning WicketTester! It’s way easier, shorter and you don’t need any web app context at all. Just do this:

    WicketTester tester = new WicketTester();
    tester.startPage(YourPage.class);
    String s = tester.getServletResponse().getDocument();

    regards,
    Tim

11. Pingback: Retrieving html from wicket components

12. for 1.5 version ( seen it on wicket forum )

    BufferedWebResponse bufferedWebResponse = new BufferedWebResponse(null);
    webPage.getRequestCycle().setResponse(bufferedWebResponse);
    webPage.render();
    return bufferedWebResponse.getText().toString();